KR20090026968A - Traffic monitoring apparatus - Google Patents

Abstract

A traffic monitoring apparatus is provided to collect wide traffic information including vehicle identification by measuring a wheel axle by using two piezo lines and one magnetic field sensor or one piezo line and two magnetic field sensors. A traffic information measuring device is composed of a connection line unit(230), a magnetic field case, and a magnetic field sensor(100). The connection line unit is buried in an asphalt intermediate layer or below. A magnetic field case includes a sensor receiving space, is buried from a surface layer to the immediate layer of the asphalt, and includes a case cover(201) exposed to the surface. The magnetic field sensor is mounted in the magnetic field case.

Description

Traffic information measuring device {TRAFFIC MONITORING APPARATUS}

The present invention relates to a traffic information measuring apparatus using a geomagnetic sensor, and in particular, by detecting the earth magnetic field distorted by the vehicle running on the road to accurately detect the traffic information of the road, such as traffic volume, vehicle presence, vehicle speed, occupancy and type of vehicle In addition to providing a grasping device, it is very convenient to maintain the road pavement in the case of rigid pavement concrete and soft pavement asphalt pavement, which has little effect on the overlapping of the pavement that is periodically performed and the repaving after cutting. A traffic information measuring apparatus.

In order to detect the information of the vehicle passing through the road, various vehicle detection devices such as loop detectors, image detectors, ultrasonic detectors, microwave detectors, and laser detectors have been used.

The loop detector is the most widely used detection device, and applies an oscillation signal to a roof coil embedded on a road surface, and detects the occupancy of the vehicle by detecting a change in the magnetic field when there is a metallic object on the road surface. Loop detectors are more vulnerable to cutting during road construction than ultrasonic and imaging methods. In addition, the roof detectors are most widely used as vehicle occupancy sensors because they are very inexpensive and have stable performance regardless of environmental conditions. Loop detectors install one or a pair per lane and use oscillating waves of different frequencies to prevent errors caused by magnetic fields induced in adjacent loop coils. As mentioned above, the loop detector has adopted this method in most cases in Korea because the detection information is more reliable and cheaper to install than other types of detectors, but the following disadvantages are pointed out.

-The loop detector is affected by the inductance change depending on the pavement of the road and the materials used. Therefore, there is a remarkable difference in performance depending on the absence of construction failure and the shape and size of the detector. That is, there are many cases where it is impossible to collect and collect erroneous data due to moisture or disconnection of the loop detector due to careless construction.

-It is necessary to control traffic flow during installation.

-Deterioration of detector performance due to road damage and deterioration of detector performance due to deformation of pavement. On-site installation is the most detectable method on the market, but no comprehensive verification has been done.

-In case of general national highways, the failure status of loop detectors is increasing by year, with 48 places in 1999, 49 places in 2000, 127 places in 2001, and 140 places in 2002. As the cause of the failure, the failure caused by road damage and disconnection is increasing very rapidly, and the suspension of operation due to the road pavement construction is also increasing.

-For highways, there is a cost for repairing damage and fault detectors once a year for one loop detector. It takes about 2 ~ 3 weeks from the service order of the roof detector to repair and the police consultation according to the selection of maintenance company and the road blockage.The damage and the failure of the loop detector are mostly caused by the lanes. For lanes where information is not collected, traffic information is provided by referring to the information of adjacent lanes.

-It is buried in the road surface, causing a breakdown over time such as damage by a vehicle or natural corrosion (approximately 2 years of endurance of the loop sensor if no loop break occurs).

-According to the internal data of the police unmanned enforcement equipment, the sensor breakdown occurs about twice a year, which is expected to be 20 ~ 30%.

As described above, the loop detector embeds the roof coil over a fairly wide ground, making installation and maintenance difficult, high frequency of breakage, and low speed vehicle detection. In particular, due to road changes in Korea, where asphalt is mostly asphalt, irregularities are generated due to temperature changes, and the breakage rate is high.

The image sensor is a method of recognizing a distribution of pixel values of a region to be detected in advance and determining whether to enter a vehicle by changing pixel values when the vehicle enters. In case of Youngsam ginseng detector, it is a non-embedded type, and the application cases are increasing recently because of the relative advantages of the inconvenience of installation work and difficulty of maintenance of buried type such as loop detector. In addition, unlike other detectors, there is an advantage that the administrator can check with the naked eye, so if the performance improvement such as resolution is supported, it is expected to be developed in the future. However, the result of image detector analysis has been pointed out that it is very sensitive to changes in climatic conditions and environment, such as deterioration of discrimination performance due to sudden changes in light quantity during rainy weather and sunset, and requires periodic maintenance because the lens needs to be cleaned. In other words, one installation cost is relatively very expensive.

Ultrasonic sensors are sensitive to climate and surrounding environment, and the detection area is conical, so there is no directivity. Microwave detectors are mainly used to obtain vehicle speed information, but they are expensive to install and require specialists for maintenance. Laser detectors require periodic maintenance for oscillator tuning, and expensive equipment to obtain accurate information.

Recently, a traffic information collection system using a geomagnetic sensor and wireless communication has been developed to overcome these disadvantages, which provides reliable traffic information in real time with relatively accurate vehicle detection, and provides easy operation of the system by solar or battery. There is a case in which a system has been developed to facilitate installation, maintenance, and management of a vehicle sensing device because an additional cable installation work is not required due to wireless data communication (application number 10-2001-0012151). However, in the long-term operation, the energy efficiency of the solar system not only decreases energy efficiency rapidly due to foreign matters such as dust, but also requires periodic maintenance for actual system operation due to moisture problems. In addition to the need to replace the batteries periodically, there is a disadvantage in that the battery does not operate normally at high or low temperatures depending on the temperature, traffic information measuring device using a geomagnetic sensor was implicated in the introduction to the field.

In order to solve the problems described above, the present invention provides a traffic information measuring device using a geomagnetic sensor, buried more than a certain depth so that the road paving over the road paving and cutting so as not to affect the resurfacing after cutting Characterized by very convenient management; Power cable and data transmission cable which is buried more than a certain depth are installed inside the protection pipe and twisted in the shape of spring, so that even if the package or protection pipe is damaged by tensile compressive stress, fatigue crack, plastic deformation, By securing the clearance length as much as twisted, it is characterized in that damage due to disconnection of the cable is prevented; While the loop detector requires a complicated sensor reinstallation process for controlling and replacing a vehicle when the sensor is damaged, the present invention provides a method of removing the geomagnetic sensor and the signal conditioner installed inside the case fixed to the package by loosening and replacing a few bolts. Its purpose is to provide a traffic information collection device that can maximize the convenience of maintenance because the traffic control and installation process is very simple.

The object of the present invention is directly applicable to the concrete of the concrete pavement, in the case of soft pavement of asphalt pavement, traffic information measuring device is installed is embedded in the asphalt divided into at least a surface layer and an intermediate layer, the asphalt intermediate layer or more A geomagnetism case and a geomagnetism sensor unit mounted to the geomagnetic case having a connecting wire part embedded in a deep position, a case cover having a geomagnetism sensor accommodation space therein, and a case cover buried over at least the surface layer and the intermediate layer and exposed to the surface layer. It can achieve by the traffic information measuring apparatus characterized by including.

Preferably, the connection wire part is characterized by consisting of a protective tube having a penetrating shape therein and a conductive wire inserted into the protective tube. More preferably, the conductive wire is wound spirally in the form of a spring.

The geomagnetic case is provided with a release layer on the outer wall, it is preferably fixed by a filler between the asphalt and the release layer, the case cover is preferably separated from the geomagnetic case. There may be a number of ways to implement it separably, but there is typically a screwing method.

By providing the traffic information measuring device considering the convenience of road pavement maintenance as described above, the reliability is consistent according to the installation conditions and the state of the package, and consistent and reliable regardless of the installation conditions and external environment. Traffic information can be collected. In addition, the loop detector is easily damaged due to disconnection or the like depending on the state of the package, whereas the apparatus of the present invention enables highly durable system operation regardless of the state of the package.

In addition, cutting and repackaging is very free regardless of the traffic information measuring device, and it is possible to restart the system with minimum traffic control and social cost by easily replacing the signal acquisition unit in case of system failure. It is done.

1 is a cross-sectional view of the asphalt structure, Figure 2 shows the plastic deformation and fatigue crack as a general damage type of asphalt pavement. Asphalt is composed of an AP surface layer 301, an AP interlayer 302, an AP base layer 303, and an auxiliary base layer 304. In the case of the loop detector which is used the most in Korea, it is generally installed on the asphalt surface layer 301 of FIG. 1 for a good response of the sensor, and a general package such as plastic deformation 311 and fatigue crack 312 of FIG. Due to the breakage of the loop detector, damage is easily caused by disconnection or the like.

In general, the AP surface layer 301 has a dynamic function of distributing the traffic load to the uppermost layer of the pavement and transmitting it to the AP base layer 303, and is constructed for the purpose of ensuring comfortable driving performance. Asphalt pavement can be replaced by the concept of cutting and overlaying, usually once every two years, depending on the concept of wear coarse. Therefore, in the case of the loop detector installed on the surface of the AP, not only damage such as disconnection can be easily generated, but also it is acting as an obstacle for maintenance of pavement for overlay or repaving.

Traffic information measuring system considering the convenience of road pavement and system operation of the present invention, the connection wire 230 is buried at a depth below the AP middle floor, and has a geomagnetic sensor receiving space therein is embedded in asphalt A geomagnetic case 200 having a case cover exposed to the surface layer and a geomagnetic sensor unit mounted on the geomagnetic case 200 are provided.

The connection wire 230 is embedded in the AP intermediate layer or deeper so as not to be affected even when the AP surface layer 301 is repackaged. The connection wire 230 is composed of a spring wire 232 wound in a spring type inside the protective tube 231 made of a corrosion-resistant material such as PVC. The geomagnetic case 200 includes a case 201 and a case cover 203 having an accommodation space therein. The geomagnetic sensor unit includes a geomagnetic sensor and a circuit unit for driving the geomagnetic sensor.

As shown in Figure 3, it can be easily installed only by cutting the joint for the circular hole and the cable for the installation of the case 202 has a feature that requires minimum traffic control and manpower. In addition, the cable for power and data transmission is installed in the middle layer below the surface, so that it can be overlaid for periodic maintenance and cutting (cutting) for re-packaging. There is an advantage that does not interfere with. The cable for power and data transmission is primarily installed in the protection tube 231 so that damage to the external stimulus is not generated. Even though this cable is protected, the protection tube may be damaged by plastic deformation and fatigue crack due to continuous vehicle load. , Even if damage occurs in the protection tube, the cable is installed by twisting in the shape of a spring to ensure a sufficient margin, characterized in that the damage caused by disconnection of the cable is prevented.

The geomagnetic sensor unit 100 is a geomagnetic sensor 101 and the circuit unit 102, and is installed inside the case 200 installed inside the circular hole formed in the package, thereby affecting external stimuli and foreign substances such as moisture and dust. It can be excluded, and after the case cover fixing screw 203 is removed in case of failure, by replacing the geomagnetic sensor unit 100 integrally, it is characterized in that the normal operation of the system speeded up with minimal traffic control is possible. In addition, the case body 202 is fixed by a filler 251, such as cemented carbide, epoxy, polyurethane, and the case body fixing screw 205, and between the case body 202 and the filler 251, grease or When a thin peeling layer 252 such as vinyl or paper is provided and the case body 202 needs to be removed, such as when repacking after cutting (cutting), the case body fixing screw 205 is loosened and the case body ( It is an object of the present invention to provide a traffic information measuring system, which is characterized by being easily disassembled by lifting 202.

The geomagnetic sensor unit 100 may be installed by forming a separate stand inside the case or may be fixed by using a screw fixing or an adhesive on the bottom of the case cover 201, and any form mounted in the case in the present invention. It should also be interpreted as including.

Hereinafter, a method of installing a traffic information measurement system according to an embodiment of the present invention will be briefly described. First, as shown in FIG. 4, the asphalt is opened in a straight line to bury the connecting wire 230 in the AP base layer 302 or deeper, and form a cylindrical hole, and then the case body 202. Buried. In this case, a temporary mounting table 400 is formed on the upper portion of the case body 202 to support the cylindrical hole, and a release layer 252 such as grease is attached to the outside of the case body 202. In this case, one conductive wire of the connection wire part 230 is connected to the inside of the case body 202 through a through hole (not shown) formed at the side or bottom of the case body 202.

Next, as shown in FIG. 5, the filler is injected through the gap formed between the injection hole 401 formed in the temporary holder 400 on the upper part of the case body 202 or the asphalt and the temporary holder 400, and the temporary holder Remove 400. As shown in FIG. 6, the case is firmly fixed to asphalt using the case body fixing screw 205, the geomagnetic sensor unit 100 is mounted therein, and the case cover 201 is upper part of the case body 202. When the case cover fixing screw 203 and the fixing screw groove 204 are fixed, the installation of the traffic information measuring device using the geomagnetic sensor is completed.

In addition, the roadside is provided with a signal processor 500 for processing a signal input from the geomagnetic sensor unit 100. It is installed by the circular perforation on the package, and is installed for the purpose of protecting the signal acquisition unit from external stimuli and foreign matters, and a thin peeling layer is formed that is isolated from the filler is very easy to remove the case 200, and the case It is installed inside, the geomagnetic sensor unit 100 to obtain a signal by the geomagnetic sensor and the circuit unit, and easily installed by the joint cutting, is installed on the intermediate layer rather than the surface layer is performed periodically (cutting) and repackaging It does not affect at all, protects the cable against external stimuli, and even if the protective tube is damaged due to plastic deformation and fatigue cracking, the cable is installed in a spring shape to secure sufficient length so that it is not easily disconnected. Received from the spring-shaped connecting wire 230 and the at least one geomagnetic sensor unit 100 built in the protective tube It is composed of a signal processing section 500 for processing a signal.

Examples of the signal processing unit 500 include a terminal connection unit 510 for connecting to at least one geomagnetic sensor unit 100, an A / D converter 104 for converting an analog input signal into digital data, and Characterized in that it consists of a signal processing unit 105 that can calculate a variety of traffic information by the signal processing the input signal.

In addition, as shown in FIG. 7, the case 200 continuously installs an existing sensor without any extra effort by installing an additional overlay case intermediate connection part 206 when the additional overlay layer 305 is installed. Can be characterized.

8 is an embodiment of a traffic information measuring apparatus using only a geomagnetic sensor. As shown in FIG. 8, the road generally includes a center line 401 and a lane separation line 402. Two geomagnetic sensor unit 100 is installed in each lane spaced apart from each other by a certain distance, it can be seen that the geomagnetic sensor unit 100 is connected to each other by the connection wire 230.

FIG. 9 is an embodiment of a traffic information measuring apparatus in which a piezo line is added as an axle sensor to the apparatus of FIG. 8. As shown in FIG. 8, at least one piezo line 110 spaced apart from each other by a predetermined distance in each lane is connected to the data processing unit 500 and the geomagnetic sensor unit by the connection wire unit 230. It can be seen that.

In the case of FIG. 9, at least two piezo lines 110 and one geomagnetic sensor or one piezo line and two geomagnetic sensors (not shown) are used to distinguish vehicle types by axle measurement compared to the embodiment of FIG. 8. It is possible to collect a wider traffic information including, further improving the reliability of the measurement response.

The present invention described above is not limited to the above-described embodiments and drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have

1 is an asphalt structure cross section.

Figure 2 shows the plastic deformation and fatigue crack as a general damage type of asphalt pavement.

Figure 3 is an embodiment of a traffic information measuring apparatus according to the present invention.

4 to 6 is an embodiment of the construction of the traffic information measuring apparatus of FIG.

7 is an explanatory diagram illustrating a situation in which an overlay layer is additionally installed in the traffic information measuring apparatus of the present invention.

8 is an embodiment of a traffic information measuring device using only a geomagnetic sensor.

FIG. 9 is an embodiment of a traffic information measuring apparatus in which a piezo line is added as an axle sensor to the apparatus of FIG. 8; FIG.

Claims (6)

As a traffic information measuring device installed at least in asphalt divided into a surface layer and an intermediate layer, A connection wire portion embedded in the asphalt intermediate layer or a deeper position; A geomagnetic case having a geomagnetic sensor accommodation space therein and having a case cover embedded over at least the surface layer and the intermediate layer and exposed to the surface layer; And And a geomagnetic sensor unit mounted on the geomagnetic case. The method of claim 1, The connecting wire unit is a traffic information measuring device, characterized in that consisting of a protective tube having a penetrating shape therein and a conductive wire inserted into the protective tube. The method of claim 2, The conductor is a traffic information measuring device, characterized in that the spiral wound in the form of a spring. The method of claim 1, The geomagnetic case is provided with a peeling layer on the outer wall, the traffic information measuring device, characterized in that fixed by the filler between the asphalt and the peeling layer. The method of claim 1, The case cover is a traffic information measuring device, characterized in that detachable from the geomagnetic case. The method of claim 1, At least one piezo line spaced apart a certain distance is further characterized in that the traffic information measuring device.

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